50 research outputs found
Cortex cis -regulatory switches establish scale colour identity and pattern diversity in Heliconius
In Heliconius butterflies, wing colour pattern diversity and scale types are controlled by a few genes of large effect that regulate colour pattern switches between morphs and species across a large mimetic radiation. One of these genes, cortex, has been repeatedly associated with colour pattern evolution in butterflies. Here we carried out CRISPR knockouts in multiple Heliconius species and show that cortex is a major determinant of scale cell identity. Chromatin accessibility profiling and introgression scans identified cis-regulatory regions associated with discrete phenotypic switches. CRISPR perturbation of these regions in black hindwing genotypes recreated a yellow bar, revealing their spatially limited activity. In the H. melpomene/timareta lineage, the candidate CRE from yellow-barred phenotype morphs is interrupted by a transposable element, suggesting that cis-regulatory structural variation underlies these mimetic adaptations. Our work shows that cortex functionally controls scale colour fate and that its cis-regulatory regions control a phenotypic switch in a modular and pattern-specific fashion
BioSimulators: a central registry of simulation engines and services for recommending specific tools
Computational models have great potential to accelerate bioscience, bioengineering, and medicine. However, it remains challenging to reproduce and reuse simulations, in part, because the numerous formats and methods for simulating various subsystems and scales remain siloed by different software tools. For example, each tool must be executed through a distinct interface. To help investigators find and use simulation tools, we developed BioSimulators (https://biosimulators.org), a central registry of the capabilities of simulation tools and consistent Python, command-line and containerized interfaces to each version of each tool. The foundation of BioSimulators is standards, such as CellML, SBML, SED-ML and the COMBINE archive format, and validation tools for simulation projects and simulation tools that ensure these standards are used consistently. To help modelers find tools for particular projects, we have also used the registry to develop recommendation services. We anticipate that BioSimulators will help modelers exchange, reproduce, and combine simulations
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
BAC-pool sequencing and analysis of large segments of A12 and D12 homoeologous chromosomes in upland cotton.
Acknowledgments
âDedicated to Dr. Ramesh Kantety, a mentor, colleague and friendâ. We would like to acknowledge the support offered by Padmini Sripathi during data analysis and submissions.
Author Contributions
Conceived and designed the experiments: RVK JZY. Performed the experiments: RB ZX SM GBW. Analyzed the data: RB. Contributed reagents/materials/analysis tools: RVK RB JZY RJK BAR. Wrote the manuscript: RB. Revised the manuscript: RB RVK JZY RGP BAR GCS. Advised the research: RVK JZY RGP BAR GCS.Author Contributions
Conceived and designed the experiments: RVK JZY. Performed the experiments: RB ZX SM GBW. Analyzed the data: RB. Contributed reagents/materials/analysis tools: RVK RB JZY RJK BAR. Wrote the manuscript: RB. Revised the manuscript: RB RVK JZY RGP BAR GCS. Advised the research: RVK JZY RGP BAR GCS.Although new and emerging next-generation sequencing (NGS) technologies have reduced sequencing costs significantly, much work remains to implement them for de novo sequencing of complex and highly repetitive genomes such as the tetraploid genome of Upland cotton (Gossypium hirsutum L.). Herein we report the results from implementing a novel, hybrid Sanger/454-based BAC-pool sequencing strategy using minimum tiling path (MTP) BACs from Ctg-3301 and Ctg-465, two large genomic segments in A12 and D12 homoeologous chromosomes (Ctg). To enable generation of longer contig sequences in assembly, we implemented a hybrid assembly method to process ~35x data from 454 technology and 2.8-3x data from Sanger method. Hybrid assemblies offered higher sequence coverage and better sequence assemblies. Homology studies revealed the presence of retrotransposon regions like Copia and Gypsy elements in these contigs and also helped in identifying new genomic SSRs. Unigenes were anchored to the sequences in Ctg-3301 and Ctg-465 to support the physical map. Gene density, gene structure and protein sequence information derived from protein prediction programs were used to obtain the functional annotation of these genes. Comparative analysis of both contigs with Arabidopsis genome exhibited synteny and microcollinearity with a conserved gene order in both genomes. This study provides insight about use of MTP-based BAC-pool sequencing approach for sequencing complex polyploid genomes with limited constraints in generating better sequence assemblies to build reference scaffold sequences. Combining the utilities of MTP-based BAC-pool sequencing with current longer and short read NGS technologies in multiplexed format would provide a new direction to cost-effectively and precisely sequence complex plant genomes.Yeshttp://www.plosone.org/static/editorial#pee
Genetic variation at CYP3A is associated with age at menarche and breast cancer risk : a case-control study
Abstract
Introduction
We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age â€50 years.
Methods
We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics.
Results
We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P
trend = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P
trend = 0.005) but not cases (P
trend = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P
het = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age â„15 years (ORhet = 0.84, 95% CI 0.75, 0.94; ORhom = 0.81, 95% CI 0.51, 1.30; P
trend = 0.002) but not for those who had their menarche age â€11 years (ORhet = 1.06, 95% CI 0.95, 1.19, ORhom = 1.07, 95% CI 0.67, 1.72; P
trend = 0.29).
Conclusions
To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels
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Risk Prediction Models for Postoperative Decompensation and Infection in Patients With Cirrhosis: A Veterans Affairs Cohort Study
Patients with cirrhosis have an increased risk of postoperative mortality for a range of surgeries; however, they are also at risk of postoperative complications such as infection and cirrhosis decompensation. To date, there are no prediction scores that specifically risk stratify patients for these morbidities.
This was a retrospective study using data of patients with cirrhosis who underwent diverse surgeries in the Veterans Health Administration. Validated algorithms and/or manual adjudication were used to ascertain postoperative decompensation and postoperative infection through 90 days. Multivariable logistic regression was used to evaluate prediction models in derivation and validation sets using variables from the recently-published Veterans Outcomes and Costs Associated with Liver Disease (VOCAL)-Penn cirrhosis surgical risk scores for postoperative mortality. Models were compared with the Mayo risk score, Model for End-stage Liver Disease (MELD)-sodium, and Child-Turcotte-Pugh (CTP) scores.
A total 4712 surgeries were included; patients were predominantly male (97.2Â %), white (63.3Â %), and with alcohol-related liver disease (35.3Â %). Through 90 postoperative days, 8.7Â % of patients experienced interval decompensation, and 4.5Â % infection. Novel VOCAL-Penn prediction models for decompensation demonstrated good discrimination for interval decompensation (C-statistic 0.762 vs 0.663 Mayo vs 0.603 MELD-sodium vs 0.560 CTP; P < .001); however, discrimination was only fair for postoperative infection (C-statistic 0.666 vs 0.592 Mayo [PÂ = .13] vs 0.502 MELD-sodium [P < .001] vs 0.503 CTP [P < .001]). The model for interval decompensation had excellent calibration in both derivation and validation sets.
We report the derivation and internal validation of a novel, parsimonious prediction model for postoperative decompensation in patients with cirrhosis. This score demonstrated superior discrimination and calibration as compared with existing clinical standards, and will be available at www.vocalpennscore.com
Risk Prediction Models for Post-Operative Mortality in Patients With Cirrhosis
Patients with cirrhosis are at increased risk of postoperative mortality. Currently available tools to predict postoperative risk are suboptimally calibrated and do not account for surgery type. Our objective was to use population-level data to derive and internally validate cirrhosis surgical risk models.
We conducted a retrospective cohort study using data from the Veterans Outcomes and Costs Associated with Liver Disease (VOCAL) cohort, which contains granular data on patients with cirrhosis from 128 U.S. medical centers, merged with the Veterans Affairs Surgical Quality Improvement Program (VASQIP) to identify surgical procedures. We categorized surgeries as abdominal wall, vascular, abdominal, cardiac, chest, or orthopedic and used multivariable logistic regression to model 30-, 90-, and 180-day postoperative mortality (VOCAL-Penn models). We compared model discrimination and calibration of VOCAL-Penn to the Mayo Risk Score (MRS), Model for End-Stage Liver Disease (MELD), Model for End-Stage Liver Disease-Sodium MELD-Na, and Child-Turcotte-Pugh (CTP) scores. We identified 4,712 surgical procedures in 3,785 patients with cirrhosis. The VOCAL-Penn models were derived and internally validated with excellent discrimination (30-day postoperative mortality C-statistic = 0.859; 95% confidence interval [CI], 0.809-0.909). Predictors included age, preoperative albumin, platelet count, bilirubin, surgery category, emergency indication, fatty liver disease, American Society of Anesthesiologists classification, and obesity. Model performance was superior to MELD, MELD-Na, CTP, and MRS at all time points (e.g., 30-day postoperative mortality C-statistic for MRS = 0.766; 95% CI, 0.676-0.855) in terms of discrimination and calibration.
The VOCAL-Penn models substantially improve postoperative mortality predictions in patients with cirrhosis. These models may be applied in practice to improve preoperative risk stratification and optimize patient selection for surgical procedures (www.vocalpennscore.com)